Objective: To modify an existent MD-300 chemostat to provide a suitable analogous oral environment for studying plaque biofilm formation, bacterial adhesion to denture base material and the oral microbial ecology. Methods: The brooder of MD-300 chemostat was modified, which incorporated removable and replaceable hydroxyapatite disks, and the chemostat’s key parameters were regulated for primary application. Results: To help maintain the chemostat under analogous oral environment, the medium used was tripticase soy broth with 2.5 g/L porcine gastric mucin, volume 1.2 L, medium flow rate 50 mL/h, culture pH maintained at 7.0 ± 0.1, temperature 37 ± 0.1°C and the air quality was a mixture of 80% N2, 10% CO2, and 10% H2. Artificial plaque biofilms conventionally developed on hydroxyapatite disks and bacterial adhesion was detected on the surface of different resin denture material in the modified MD-300 chemostat. Conclusion: The modified MD-300 chemostat has considerable potential in studying artificial dental plaque biofilm development and bacterial ecologic relationship, as well as in comparing bacterial adhesion to different materials under analogous oral environment.